Biometric authentication is one of authentication techniques. The biometric authentication is an authentication utilizing biological information (information enabling identifying individuals by one's body or behavior). For example, when the biological information in a target person of identity verification (a person whose identity is to be confirmed) is inputted, an authentication device which performs the biometric authentication compares the inputted biological information with a registered biological information preliminarily registered. The authentication device determines that the target person of identity verification is an actual person who is registered the registered biological information in the case the inputted biological information matches or closely resembles the registered biological information. On the other hand, in the case the inputted biological information does not resemble the registered biological information, the authentication device determines the target person of identity verification is not the person who registered the biological information.
The biometric authentication types include unimodal authentication and multimodal authentication. The unimodal authentication is an authentication method using one biological information in a target person of identity verification. The multimodal authentication is an authentication method using multiple types of biological information in a target person of identity verification. An example of a method of performing the multimodal authentication is shown in NPL1. In the method shown in NPL1, the authentication device calculates a score for each type of inputted biological information based on the comparison between the inputted multiple types of biological information and the registered biological information. Then, the authentication device determines whether the target person of identity verification is the registered person based on an integrated score that is an integration of the calculated scores.
Since such multimodal authentication utilizes more biological information than unimodal authentication, a highly precise authentication (in other words, an authentication whose authentication result is highly reliable) is said to be possible.